GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC C0131 00: ABS Pressure Circuit No Additional Information

DTC C0131 4B: ABS Pressure Circuit Calibration Not Learned

DTC C0131 5A: ABS Pressure Circuit Calibration Not Learned Plausibility Failure

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

ABS Pressure Circuit

C0131 00

C0131 00

C0131 00

--

Pressure Circuit Calibration Not Learned

--

--

--

C0131 4B

Pressure Circuit Calibration Not Learned Plausibility Failure

--

--

--

C0131 5A

Circuit/System Description

The electronic brake control module (EBCM) uses input from the brake pressure sensor for more accurate control during a Vehicle Stability Enhancement System (VSES) event.

Conditions for Running the DTC

    • The ignition is ON.
    • Ignition voltage is greater than 9.5 volts

Conditions for Setting the DTC

    • Pressure signal does not correlate to estimated pressure over time.
    • Brake signal does not correlate to pressure signal.
    • Signal is erratic and changes faster than physically allowed.

Action Taken When the DTC Sets

    • The EBCM disables the VSES and TCS for the duration of the ignition cycle.
    • The electronic stability control (ESC) telltale turns ON.

Conditions for Clearing the DTC

    • The condition for setting the DTC is no longer present and the DTC is cleared with a scan tool.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The pressure sensor is integral to the brake pressure modulator valve (BPMV). The pressure sensor is not serviceable.

Inspect the brake pressure sensor contacts for proper connections.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System Connector End Views

Description and Operation Reference

ABS Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Scan Tool Data List for EBCM

Circuit/System Testing

  1. Apply and release brake pedal. Verify brake lamps operate properly.
  2. If brake lamps do not operate properly, refer to Symptoms - Lighting Systems .
  3. Replace EBCM/brake pressure modulator valve (BPMV) assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Electronic Brake Control Module Replacement
    •  Control Module References for EBCM replacement, setup, and programming